1. Field of the Invention
The present invention relates to an IC card having improved junction strength between a panel and a frame.
2. Description of the Prior Art
FIG. 1 is a perspective view showing an example of a conventional IC card, FIG. 2 is an exploded perspective view of FIG. 1, and FIG. 3 is a sectional view taken along the plane III--III of FIG. 1.
Referring to FIGS. 1 to 3, an IC card 1 consists of a rectangular frame 2, a wiring board 3, and a pair of panels 4 and 5. Electronic parts 6 such as a semiconductor memory or the like are installed on a top and a bottom surface of the wiring board 3, respectively, and a hole 7 is formed at the central part of the wiring board 3.
The frame 2 is made of synthetic resin and has openings 8 on its top and its bottom surface, respectively. A protruding supporter 9 for supporting the wiring board 3 is provided on an inner surface of the frame 2 along a circumferential direction, and an arm 10 having a projection 11 is provided at a central part of the frame 2 along a cross direction. A concavity 12 for supporting the panel 4 is formed on the top surface of the frame 2 along a circumferential direction, while another concavity 13 (see FIG. 3) is formed on the bottom surface of the frame 2 along a circumferential direction, similarly to the concavity 12. A plurality of electrodes 14 for inserting contact pins (not shown) are provided on an end of the frame 2.
Each of the panels 4 and 5 is made of metal, and has a rectangular form.
The IC card 1 is fabricated as follows: First, the projection 11 of the frame 2 is passed through the hole 7 of the wiring board 3, and a peripheral part of the wiring board 3 is put on the convex supporter 9. In that state, a tip end of the projection 11 is crimped while being heated to form a crimping part 11a as shown in FIG. 4, whereby the wiring board 3 with the electronic parts 6 is installed in the frame 2 and the electrodes 14 are electrically connected with the electronic parts 6 through the wiring board 3. Thereafter, the panels 4 and 5 are glued to the concavities 12 and 13 of the frame 2 through adhesive materials 15 such as an adhesive sheet, adhesive bond or the like, respectively, whereby the panels 4 and 5 cover the openings 8 of the frame 2 while containing the wiring board 3 with the electronic parts 6 in the frame 2.
With the above conventional IC card 1, the panels 4 and 5 are attached to the frame 2 only by the adhesive strength of the adhesive materials 15. As a result, a gap may form between the panels 4, 5 and frame 2 owing to the reduction of the adhesive strength with the lapse of time, or the panel 4 or 5 may be partially separated from the frame 2 when the IC card 1 is bent, to thereby deteriorate the quality of the IC card 1.